Water Body Name: | Cottonwood Creek (San Marcos Creek watershed) |
Water Body ID: | CAR9045100020011009142248 |
Water Body Type: | River & Stream |
DECISION ID |
5281 |
Region 9 |
Cottonwood Creek (San Marcos Creek watershed) |
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Pollutant: | Phosphorus |
Final Listing Decision: | Delist from 303(d) list (TMDL required list) |
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006) |
Revision Status | Revised |
Reason for Delisting: | Flaws in original listing |
Impairment from Pollutant or Pollution: | Pollutant |
Regional Board Conclusion: | Regional Board Conclusion:
This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. A large number of samples exceed the Basin Plan water quality goal of 0.1 mg/L in stream and flowing waters for Phosphorus. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Four of 4 samples exceeded the basin plan water quality goal and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. State Board Review and Conclusion: The original listing in 2006 applied Table 3.1 where the minimum sample requirement is 2 samples. However, Region 9 considers phosphorus a conventional pollutant and as such, Table 3.2 should have been applied with a minimum requirement of 5 samples. State Board staff has re-evaluated the original listing and made a recommendation to Delist for phosphorus. The revised recommendation is as follows: This pollutant is being considered for removal from the section 303(d) list under section 4 of the Listing Policy. Under this section an existing listing may be removed if the listing was based on faulty data and it is demonstrated that the listing would not have occurred in the absence of such faulty data. One line of evidence is available in the administrative record to assess this pollutant. Four of four samples exceed the Basin Plan water quality goal of 0.1 mg/L in stream and flowing waters for Phosphorus. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of removing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Four of 4 samples exceeded the basin plan water quality goal and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. This pollutant should not have been listed in 2006. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
Regional Board Decision Recommendation: | No new data were assessed for 2008. The decision has not changed. |
State Board Review of Regional Board Conclusion and Recommendation: | |
State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the following changes to the decision:
The water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards for the pollutant are not exceeded. |
USEPA Action (if applicable): | |
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LOE ID: | 3198 | ||||
Pollutant: | Phosphorus | ||||
LOE Subgroup: | Pollutant-Water | ||||
Matrix: | Water | ||||
Fraction: | Total | ||||
Beneficial Use: | Warm Freshwater Habitat | ||||
Number of Samples: | 4 | ||||
Number of Exceedances: | 4 | ||||
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
Data Used to Assess Water Quality: | Four of 4 samples exceeding basin plan goal (SWAMP, 2004). | ||||
Data Reference: | Placeholder reference 2006 303(d) | ||||
SWAMP Data: | SWAMP | ||||
Water Quality Objective/Criterion: | Waters shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growth causes nuisances or adversely affects beneficial uses. | ||||
Objective/Criterion Reference: | Placeholder reference 2006 303(d) | ||||
Evaluation Guideline: | Water Quality Control Plan for the San Diego Basin Goal of 0.1 mg/l in stream and flowing waters. | ||||
Guideline Reference: | Placeholder reference 2006 303(d) | ||||
Spatial Representation: | One station in Cottonwood Creek: 33.18147 -117.32893 | ||||
Temporal Representation: | Samples were collected from March through September of 2002. | ||||
Environmental Conditions: | |||||
QAPP Information: | SWAMP Quality Assurance Plan | ||||
QAPP Information Reference(s): | |||||
DECISION ID |
5290 |
Region 9 |
Cottonwood Creek (San Marcos Creek watershed) |
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Pollutant: | Sediment Toxicity |
Final Listing Decision: | Do Not Delist from 303(d) list (TMDL required list) |
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006) |
Revision Status | Revised |
Sources: | Unknown Nonpoint Source | Unknown Point Source | Urban Runoff/Storm Sewers |
Expected TMDL Completion Date: | 2019 |
Impairment from Pollutant or Pollution: | Pollutant |
Regional Board Conclusion: | This pollutant is being considered for removal from the section 303(d) list under section 4.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status.
Two lines of evidence are available in the administrative record to assess this pollutant. Seven of samples exceed the water quality objective for toxicity. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Seven of eight samples exceeded the toxicity water quality objective and this exceeds the allowable frequency listed in Table 4.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. |
Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded. |
State Board Review of Regional Board Conclusion and Recommendation: | |
State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
USEPA Action (if applicable): | USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant. |
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LOE ID: | 3197 | ||||
Pollutant: | Sediment Toxicity | ||||
LOE Subgroup: | Toxicity | ||||
Matrix: | Sediment | ||||
Fraction: | Total | ||||
Beneficial Use: | Warm Freshwater Habitat | ||||
Number of Samples: | 4 | ||||
Number of Exceedances: | 3 | ||||
Data and Information Type: | Toxicity testing of sediments | ||||
Data Used to Assess Water Quality: | Three out of four samples displayed statistically significant toxicity in the survival endpoint when compared to the negative control based on a statistical test with alpha of less than 5%. All samples were tested using the 10-day Hyallela azteca test. Note that all four samples actually had significant toxicity relative to the control, but only the three samples without any QA qualifiers were considered as exceedances (SWAMP, 2004). | ||||
Data Reference: | Placeholder reference 2006 303(d) | ||||
SWAMP Data: | SWAMP | ||||
Water Quality Objective/Criterion: | All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropriate methods as specified by the Regional Board (Region 9 Basin Plan, pages 3-15 to 3-16; September 8, 1994). | ||||
Objective/Criterion Reference: | Placeholder reference 2006 303(d) | ||||
Evaluation Guideline: | |||||
Guideline Reference: | |||||
Spatial Representation: | All samples were collected from one station, Cottonwood Creek 2. | ||||
Temporal Representation: | Samples were collected from March 2002 through September 2002. Toxicity in the survival endpoint was detected in samples collected on March 13, 2002, June 4, 2002 and September 17, 2002. | ||||
Environmental Conditions: | Cottonwood Creek = 904.51 | ||||
QAPP Information: | SWAMP QAPP. | ||||
QAPP Information Reference(s): | |||||
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LOE ID: | 21379 | ||||
Pollutant: | Toxicity | ||||
LOE Subgroup: | Population/Community Degradation | ||||
Matrix: | Water | ||||
Fraction: | None | ||||
Beneficial Use: | Warm Freshwater Habitat | ||||
Number of Samples: | 4 | ||||
Number of Exceedances: | 4 | ||||
Data and Information Type: | Ambient toxicity testing (chronic) | ||||
Data Used to Assess Water Quality: | Four samples were collected at Cottonwood Creek station 2, 904CBCWC2. Samples were collected March, April, June and September 2002.
Samples showed significant toxicity levels (SL) in the following tests: Selenastrum algae growth test - three of the four samples exhibited toxicity. Ceriodaphnia dubia survival/reproductive test - three of the four samples exhibited toxicity. The test results are from California's Surface Water Ambient Monitoring Program Report, 2007. |
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Data Reference: | Monitoring data for Region 9 | ||||
SWAMP Data: | SWAMP | ||||
Water Quality Objective/Criterion: | From the Basin Plan, all waters shall be free of toxic substances that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. | ||||
Objective/Criterion Reference: | Water Quality Control Plan for the San Diego Basin | ||||
Evaluation Guideline: | According to SWAMP, waters are considered toxic when samples show significant toxicity levels (SWAMP code SL) when compared to a negative control. Significant toxicity is determined when statistical tests result in an alpha of less than 5% and percent control values less than the evaluation threshold. | ||||
Guideline Reference: | Waste Discharge Requirements for Discharges of Urban Runoff From the Municipal Separate Storm Sewer Systems Draining the Watersheds of the County of San Diego, the Incorporated Cities of San Diego, the San Diego Unified Port District, and the San Diego County Regional Airport. Order No. R9-2007-0001 | ||||
Spatial Representation: | Samples were collected at Cottonwood Creek station 2,(904CBCWC2). (Latitude 30.0486, Longitude -117.2954). | ||||
Temporal Representation: | Samples were collected in March, April, June and September 2002. | ||||
Environmental Conditions: | |||||
QAPP Information: | Quality control for the chemical analysis portion of this study was conducted in accordance with the California's Surface Water Ambient Monitoring Program. | ||||
QAPP Information Reference(s): | 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA | ||||
DECISION ID |
16711 |
Region 9 |
Cottonwood Creek (San Marcos Creek watershed) |
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Pollutant: | Total Nitrogen as N |
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list) |
Last Listing Cycle's Final Listing Decision: | New Decision |
Revision Status | Revised |
Impairment from Pollutant or Pollution: | Pollutant |
Regional Board Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.
One line of evidence is available in the administrative record to assess this pollutant. Four of the 4 samples exceed the water quality objective. According to table 3.2 of the Listing Policy, the minimum sample requirement to assess conventional pollutants is 5. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Four of the 4 samples exceeded the Basin Plan objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded due to limited samples. |
State Board Review of Regional Board Conclusion and Recommendation: | |
State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
USEPA Action (if applicable): | |
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LOE ID: | 6551 | ||||
Pollutant: | Total Nitrogen as N | ||||
LOE Subgroup: | Pollution | ||||
Matrix: | Water | ||||
Fraction: | None | ||||
Beneficial Use: | Warm Freshwater Habitat | ||||
Number of Samples: | 4 | ||||
Number of Exceedances: | 4 | ||||
Data and Information Type: | Fixed station physical/chemical monitoring (conventional pollutants only) | ||||
Data Used to Assess Water Quality: | All 4 samples collected show excessive nitrogen concentrations according to results in California's Surface Water Ambient Monitoring Program Report, 2007. Water samples were collected in March, April June, and September 2002. | ||||
Data Reference: | Water Quality Control Plan for the San Diego Basin | ||||
SWAMP Data: | SWAMP | ||||
Water Quality Objective/Criterion: | Water bodies shall not contain biostimulatory substances in concentrations that promote aquatic growth to the extent that such growths cause nuisance or adversely affect beneficial uses (RWQCB, 2007).
A desired goal in order to prevent plant nuisance in streams and other flowing waters appears to be 0.1 mg/L total phosphorus, P. These values are not to be exceeded more than 10% of the time unless studies of the specific water body in question clearly show that water quality objective changes are permissible and changes are approved by the Regional Board. Analogous threshold values have not been set for nitrogen compounds; however, natural ratios of nitrogen to phosphorus are to be determined by surveillance and monitoring and upheld. If data are lacking, a ratio of N:P = 10:1, on a weight to weight basis shall be used (RWQCB, 2007). |
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Objective/Criterion Reference: | Water Quality Control Plan for the San Diego Basin | ||||
Evaluation Guideline: | |||||
Guideline Reference: | Water Quality Control Plan for the San Diego Basin | ||||
Spatial Representation: | Samples were collected at Cottonwood Creek station 904CBCWC2; (Latitude 33.0486, Longitude -117.2954). | ||||
Temporal Representation: | Water samples were collected in March, April June, and September 2002. | ||||
Environmental Conditions: | |||||
QAPP Information: | Quality control for the chemical analysis portion of this study was conducted in accordance with the California's Surface Water Ambient Monitoring Program. | ||||
QAPP Information Reference(s): | 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA | ||||
DECISION ID |
16389 |
Region 9 |
Cottonwood Creek (San Marcos Creek watershed) |
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Pollutant: | Selenium |
Final Listing Decision: | List on 303(d) list (TMDL required list) |
Last Listing Cycle's Final Listing Decision: | New Decision |
Revision Status | Revised |
Sources: | Source Unknown |
Expected TMDL Completion Date: | 2019 |
Impairment from Pollutant or Pollution: | Pollutant |
Regional Board Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.
One line of evidence is available in the administrative record to assess this pollutant. Four of the 4 samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Four of 4 samples exceed the CTR criterion and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem. |
State Board Review of Regional Board Conclusion and Recommendation: | |
State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
USEPA Action (if applicable): | USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant. |
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LOE ID: | 8517 | ||||
Pollutant: | Selenium | ||||
LOE Subgroup: | Pollutant-Water | ||||
Matrix: | Water | ||||
Fraction: | Dissolved | ||||
Beneficial Use: | Warm Freshwater Habitat | ||||
Number of Samples: | 4 | ||||
Number of Exceedances: | 4 | ||||
Data and Information Type: | Fixed station physical/chemical (conventional plus toxic pollutants) | ||||
Data Used to Assess Water Quality: | Four water samples were collected at Cottonwood Creek station 2, 904CBCWC2 on March, April, June, and September 2002. All samples showed excessive sulfate concentrations according to results in California's Surface Water Ambient Monitoring Program Report, 2007. | ||||
Data Reference: | Monitoring data for Region 9 | ||||
SWAMP Data: | SWAMP | ||||
Water Quality Objective/Criterion: | CTR Freshwater Chronic (CCC) 5 ug/L; (U.S. EPA, 2000). | ||||
Objective/Criterion Reference: | Water Quality Control Plan for the San Diego Basin | ||||
Evaluation Guideline: | |||||
Guideline Reference: | Water Quality Standards; Establishment of Numeric Criteria for Priority Toxic Pollutants for the State of California; Rule. 40 CFR Part 131. U.S. Environmental Protection Agency, Region IX, Water Division, San Francisco, CA | ||||
Spatial Representation: | Water samples were collected at Cottonwood Creek station 2, 904CBCWC2; (Latitude 33.0486, Longitude -117.2954). | ||||
Temporal Representation: | Water samples were collected in March, April June, and September 2002. | ||||
Environmental Conditions: | |||||
QAPP Information: | Quality control for the chemical analysis portion of this study was conducted in accordance with the California's Surface Water Ambient Monitoring Program. | ||||
QAPP Information Reference(s): | 2002. Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. California Department of Fish and Game, Monterey, CA | ||||
DECISION ID |
4746 |
Region 9 |
Cottonwood Creek (San Marcos Creek watershed) |
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Pollutant: | Benthic-Macroinvertebrate Bioassessments |
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list) |
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2006) |
Revision Status | Original |
Impairment from Pollutant or Pollution: | Pollutant |
Regional Board Conclusion: | Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category.
This conclusion is based on the staff findings that the single line of evidence in the record to assess this pollutant consists of bioassessment data. This information on its own is insufficient to determine with the confidence and power required by the Listing Policy since Section 3.9 of the policy states that this data must be associated with numerical water quality data. |
Regional Board Decision Recommendation: | After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded. |
State Board Review of Regional Board Conclusion and Recommendation: | |
State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
USEPA Action (if applicable): | |
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LOE ID: | 3195 | ||||
Pollutant: | Benthic-Macroinvertebrate Bioassessments | ||||
LOE Subgroup: | Population/Community Degradation | ||||
Matrix: | -N/A | ||||
Fraction: | Not Recorded | ||||
Beneficial Use: | Warm Freshwater Habitat | ||||
Number of Samples: | 0 | ||||
Number of Exceedances: | 0 | ||||
Data and Information Type: | Not Specified | ||||
Data Used to Assess Water Quality: | The Cottonwood Creek and Encinitas Creek Bioassessment Study Report was written in December 2003. The report states that, "The stream bioassessment survey at Cottonwood Creek indicated that reaches of the stream upstream and downstream of the water purification facility are very similar in the benthic macroinvertebrate community composition. Chrinonmid midges, the black fly Simulium, and ostracod crustaceans dominated both sites. The Index of Biotic Integrity was substantially higher downstream of the water purification facility, due to lower percentage of non-insect taxa and a lower percentage of tolerant taxa." (City of Encinitas, 2003). | ||||
Data Reference: | Placeholder reference 2006 303(d) | ||||
SWAMP Data: | Non-SWAMP | ||||
Water Quality Objective/Criterion: | No objective was found. | ||||
Objective/Criterion Reference: | Placeholder reference 2006 303(d) | ||||
Evaluation Guideline: | |||||
Guideline Reference: | |||||
Spatial Representation: | The UV system is along Cottonwood Creek before it enters Moonlight Beach. Samples for the Bioassessment were collected upstream and downstream of the treatment facility. | ||||
Temporal Representation: | The report for the study is dated December 2003. | ||||
Environmental Conditions: | |||||
QAPP Information: | Some QA information is included in the report titled Cottonwood Creek and Encinitas Creek Bioassessment Study. Prepared by MEC Analytical Systems, Inc. for the City of Encinitas, December 2003.The report includes information regarding sample site selection and description, sample collection procedures, laboratory processing and analysis, and data analysis. | ||||
QAPP Information Reference(s): | |||||
DECISION ID |
4745 |
Region 9 |
Cottonwood Creek (San Marcos Creek watershed) |
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Pollutant: | Turbidity |
Final Listing Decision: | Do Not List on 303(d) list (TMDL required list) |
Last Listing Cycle's Final Listing Decision: | Do Not List on 303(d) list (TMDL required list)(2006) |
Revision Status | Original |
Impairment from Pollutant or Pollution: | Pollutant |
Regional Board Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status.
One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the water quality objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the 24 samples exceeded the Basin Plan objective of more than 10% of the time during any one year period is 20 NTU. water quality objective and this does not exceed the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
Regional Board Decision Recommendation: | No new data were assessed for 2008. The decision has not changed. |
State Board Review of Regional Board Conclusion and Recommendation: | |
State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
USEPA Action (if applicable): | |
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LOE ID: | 3196 | ||||
Pollutant: | Turbidity | ||||
LOE Subgroup: | Pollutant-Water | ||||
Matrix: | Water | ||||
Fraction: | None | ||||
Beneficial Use: | Warm Freshwater Habitat | ||||
Number of Samples: | 24 | ||||
Number of Exceedances: | 0 | ||||
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
Data Used to Assess Water Quality: | Data were collected by the City of Encinitas from 05/2002 to 09/2002. None of the 24 samples were in exceedance. | ||||
Data Reference: | Placeholder reference 2006 303(d) | ||||
SWAMP Data: | Non-SWAMP | ||||
Water Quality Objective/Criterion: | From the Basin Plan: For inland surface waters and all beneficial uses, the turbidity concentration not to be exceeded more than 10% of the time during any one year period is 20 NTU. | ||||
Objective/Criterion Reference: | Placeholder reference 2006 303(d) | ||||
Evaluation Guideline: | |||||
Guideline Reference: | |||||
Spatial Representation: | Samples were collected along Cottonwood Creek at Third and B Streets. Samples were collected at 2 other locations from the creek to the mixing zone. The next location is post-treatment, but still part of the creek (and entered in the database as such) and the 3rd location is in the mixing zone and entered into the database as the Pacific Shoreline, San Marcos HA. | ||||
Temporal Representation: | Samples were collected from 05/28/2002 to 09/11/2002. | ||||
Environmental Conditions: | |||||
QAPP Information: | The Moonlight Beach Urban Runoff Treatment Facility Quality Assurance Project Plan, City of Encinitas. Refer Correspondence to Katherine Weldon.Considered an acceptable QAPP by the SWRCB. | ||||
QAPP Information Reference(s): | |||||
DECISION ID |
5345 |
Region 9 |
Cottonwood Creek (San Marcos Creek watershed) |
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Pollutant: | DDT (Dichlorodiphenyltrichloroethane) |
Final Listing Decision: | List on 303(d) list (TMDL required list) |
Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006) |
Revision Status | Original |
Sources: | Source Unknown |
Expected TMDL Completion Date: | 2019 |
Impairment from Pollutant or Pollution: | Pollutant |
Regional Board Conclusion: | This pollutant is being considered for placement on the section 303(d) list under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status.
One line of evidence is available in the administrative record to assess this pollutant. A sufficient number of samples exceed the CTR freshwater criteria. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Two of four samples exceeded the CTR freshwater criteria and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
Regional Board Decision Recommendation: | No new data were assessed for 2008. The decision has not changed. |
State Board Review of Regional Board Conclusion and Recommendation: | |
State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
USEPA Action (if applicable): | USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant. |
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LOE ID: | 3199 | ||||
Pollutant: | DDT (Dichlorodiphenyltrichloroethane) | ||||
LOE Subgroup: | Pollutant-Water | ||||
Matrix: | Water | ||||
Fraction: | Total | ||||
Beneficial Use: | Warm Freshwater Habitat | ||||
Number of Samples: | 4 | ||||
Number of Exceedances: | 2 | ||||
Data and Information Type: | PHYSICAL/CHEMICAL MONITORING | ||||
Data Used to Assess Water Quality: | Four water samples, two samples exceeding (SWAMP, 2004). | ||||
Data Reference: | Placeholder reference 2006 303(d) | ||||
SWAMP Data: | SWAMP | ||||
Water Quality Objective/Criterion: | No individual pesticide or combination of pesticides shall be present in the water column, sediments or biota at concentration(s) that adversely affect beneficial uses.
California Toxic Rule: Freshwater Chronic .001 mg/L. Human Health-FW (water & organisms) .00059 mg/L. |
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Objective/Criterion Reference: | Placeholder reference 2006 303(d) | ||||
Evaluation Guideline: | |||||
Guideline Reference: | |||||
Spatial Representation: | One station at Cottonwood Creek: 33.18147 -117.32893. | ||||
Temporal Representation: | Samples were collected from March through September of 2002. | ||||
Environmental Conditions: | San Marcos Creek Watershed 904.51. | ||||
QAPP Information: | SWAMP Quality Assurance Plan. | ||||
QAPP Information Reference(s): | |||||